J, W. Stntlter — Sources of YorJi-a/iire Boulders. 17 



V. — The Sources and Distribution of the Far-Travelled 

 Boulders of East Yorkshire. 



By J. W. Stather, F.G.S. 



ABOUT ten years ago, when studying the drifts of East Yorkshire, 

 Mr. G. W. Lamplugh counted and I'oughly classified the larger 

 boulders of Flamborough Head and other selected localities on the 

 coast. This work has been continued by members of the Hull 

 Geological Society, who have up to the present time recorded nearly 

 four thousand boulders, of twelve inches and upwards in diameter. 

 To avoid possible eiTor, arising from the moving beach and other 

 causes, only the boulders actually in place in the clay were noted, or 

 such as had obviously recently fallen from the cliffs. The whole 

 of the coastline from Spurn to Flamborough has been surveyed in 

 this way, and also portions of the coast north of Flamborough as far 

 as Saltburn. The lists thus prepared have been published from 

 time to time by the Hull Geological Society and by the Erratic 

 Blocks Committee of the British Association. 



These lists bring to light several interesting and previously 

 unnoticed facts with regard to the distribution of the far-travelled 

 boulders, especially when the lists obtained at Dimlington and 

 Eedcliff in South Yorkshire are compared with the lists from 

 Upgang and Saltburn in the north. Before, however, discussing the 

 statistics of the boulders, it will be advisable to give a brief 

 description of the localities where the lists were compiled. 



(i) Dimlington is situated on the sea-coast near the southern 

 extremity of Holderness. The cliffs average about eighty feet in 

 height for upwards of tvvo miles, and are entirely composed of 

 glacial material, chiefly boulder-clay. Here were noted 334 boulders 

 of twelve inches and upwards in diameter.^ 



(ii) Eedcliff is on the north shore of the Humber, near North 

 Ferriby, and is twenty-four miles west-north-west of Dimlington. 

 The cliff continues along the Humber side for two-thirds of a mile 

 with an average height of eighteen feet, and together with the 

 adjacent beach is composed of boulder-clay. The boulders recorded 

 here were 373 in number.- 



(iii) Upgang is one and a half miles north of Whitby ; the cliff 

 sections are one hundred feet or more in height, and consist largely 

 of boulder-clay. In this neighbourhood Mr. Lamplugh counted and 

 classified two hundred boulders of twelve inches and upwards in 

 diameter, the majority of which were of local origin ; the percentages 

 given in the table below are based on his list.^ 



(iv) The cliffs between Saltburn and Eedcar present the most 

 northern exposure of boulder-clay on the Yorkshire coast. These 

 sections yielded 133 boulders of twelve inches and upwards in 

 diameter.* 



• Trans. Hull Geol. Soc, vol. iii, p. (J. 



^ rroc. Yorkshire Geol. and Polytech. Soc, vol. xiii, pt. 2, p. 211. 

 ^ Ibid., vol. xi, i)t. 3, p. 403. 



* Trans. Hull Geol. Soc, vol. iii, p. 7. 



DECADE IV. — VOL. VIII. — NO. I. 2 



